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To address the issue of accuracy in Simultaneous Localization and Mapping (SLAM) for forested areas, a novel point cloud adaptive filtering algorithm is proposed in the paper, based on point cloud data obtained by backpack Light Detection and Ranging (LiDAR). The algorithm employs a K-D tree to construct the spatial position information of the 3D point cloud, deriving a linear model that is the guidance information based on both the original and filtered point cloud data. The parameters of the linear model are determined by minimizing the cost function using an optimization strategy, and a guidance point cloud filter is subsequently constructed based on these parameters. The results demonstrate that, comparing the diameter at breast height (DBH) and tree height before and after filtering with the measured true values, the accuracy of SLAM mapping is significantly improved after filtering. The Mean Absolute Error (MAE) of DBH before and after filtering are 2.20 cm and 1.16 cm; the Root Mean Square Error (RMSE) values are 4.78 cm and 1.40 cm; and the relative RMSE values are 29.30% and 8.59%. For tree height, the MAE before and after filtering are 0.76 m and 0.40 m; the RMSE values are 1.01 m and 0.50 m; the relative RMSE values are 7.33% and 3.65%. The experimental results validate that the proposed adaptive point cloud filtering method based on guided information is an effective point cloud preprocessing method for enhancing the accuracy of SLAM mapping in forested areas. [ABSTRACT FROM AUTHOR]

The loess hilly area consists of a slope–gully system, which promotes erosion; as such. it is one of the most intensely eroded areas in the world. The construction of check dams can effectively control water and soil loss of slope gullies. However, existing studies focus on the benefits of intercepting runoff and sediments at dam sites, while ignoring the change law of hydrological processes with respect to progressing dam land sedimentation. Moreover, past studies focus on the "runoff–sediment" or "flood–sediment" relationships, but rarely consider the "hydrodynamics–runoff" and "hydrodynamics–sediment" dynamics. Therefore, in this study, we developed five physical models of slope–gully systems for dam land sedimentation depths of 0, 1, 2, 3, and 4 m, in order to explore the effects of sedimentation on runoff–sediment–hydrodynamic processes. The runoff and sediment yield of the slope–gully system decreased with increasing siltation depth. The spatial and temporal distributions of the hydrodynamic parameters were different. The Reynolds number (Re), runoff energy consumption (ΔE), and runoff power (P) increased with rainfall time, whereas runoff shear stress (τ) and Froude number (Fr) did not show a significant trend over time. Re and ΔE could better describe the runoff process of the slope–gully system, while P and ΔE could better simulate the sedimentation process. Notably, our study can provide a scientific basis for establishing effective erosion prediction models to estimate the water erosion process of slope–gully systems. [ABSTRACT FROM AUTHOR]

The diversity of the carrier transport mechanism in the resistive switching process remains a significant obstacle for the design and application of resistive random access memory (RRAM) devices. In this study, the influence of annealing on the dielectric properties of the Ti/HfOx/Pt RRAM device and its associated carrier transport mechanism is investigated. The results reveal that the current conduction in both annealed and unannealed devices is primarily attributed to grain boundary (GB) relaxation, with only the GB acting as a depletion layer that induces dielectric relaxation. Furthermore, annealing decreases the interfacial polarization and changes the relaxation time at the GB. In addition, the charge carriers exhibit nearest‐neighbor hopping conduction at a higher temperature in Ti/HfOx/Pt RRAM devices, whereas variable‐range‐hopping conduction occurs at lower temperatures. Long‐range charge carrier transport also plays a significant role in the conduction process. To offer a deeper understanding of the conduction processes in the Ti/HfOx/Pt RRAM device, a carrier transport model is proposed, which provides valuable insights into the intricate mechanisms governing conduction in these devices. [ABSTRACT FROM AUTHOR]

Supercapacitors often deliver a significantly high-power density with a long cycling life but low energy density. An exceedingly promising approach is to construct asymmetric supercapacitors (ASCs) reconciling the compromise between power density and energy density. However, ASCs combining transition metal oxides (TMOs) and activated carbon (AC) struggle to improve energy density due to a vast difference in their specific capacitance. To cross this hurdle, we first proposed a new strategy to construct the ASCs with α-MoO3 as the anode and conductive polymer polypyrrole (PPy) as the cathode. The remarkable features of α-MoO3, including its layered structure and ultra-high specific capacitance, along with the stability and fast charge–discharge ability of PPy, have contributed significantly to the augmentation of power density and energy density in ASCs. Taking advantage of these bright features, the operation voltage for α-MoO3//PPy is effectively expanded to 2.0 V, exhibiting a high energy density of 25.9 W h kg−1 at 1538 W kg−1. Furthermore, the energy density presented a remarkable recovery rate, reaching 91.04% of its initial state after undergoing full rate tests. These conclusions reveal that the construction of α-MoO3//PPy can effectively enhance the energy density and power density of supercapacitors. [ABSTRACT FROM AUTHOR]

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Lithium-ion batteries (LIBs) suffer from charging difficulties, capacity decay, and severe ageing in a low-temperature environment. In this work, we suggest a theoretical study and strategy for improving the low-temperature resistance of LiMn2O4(LMO) pouch cells, by introducing a photothermal conversion layer composed of copper and single-walled carbon nanotubes. A three-dimensional electrochemical–thermal coupling model for a lithium manganate battery is established, in which the photothermal conversion layer is attached on the surface of the cathode collector, and the effect of lug design is also discussed. The changes in the battery temperature field, and improvements in electrochemical performance before and after light preheating, are analyzed. The results show that, when the photothermal conversion film is applied, the LMO pouch cell's temperature rises 2.7 °C/min in a −5 °C environment, and the surface-temperature averaging is improved. The concentration of lithium embedded in the anode is significantly increased, and the charging speed is enhanced by 20%. The batteries with a single-sided lug design exhibit better performance compared with those with a two-sided lug design. Validation of the presented model is performed, by comparing it with the experimental Panasonic UF653445ST commercial battery datasheet. This work provides theoretical guidance on improving the low-temperature performance of pouch cells, based on the photothermal conversion method. [ABSTRACT FROM AUTHOR]

Linear active disturbance rejection control (LADRC) has been widely used to improve the tracking accuracy and anti-disturbance performance of telescope servo control under disturbances. However, the linear extended state observer (LESO) is sensitive to noise, and its bandwidth is limited by the resonant frequency of the telescope. To enhance the LARDC's ability to attenuate disturbances, a novel cascade anti-disturbance structure (NCADS) with LADRC on the outer speed loop and a nonlinear disturbance observer (NDOB) on the inner current loop is proposed. The NDOB compensates for the dominant disturbance through feedforwarding the q-axis current reference, and the LESO compensates for the residual disturbance on the outer speed loop. First, the NCADS is introduced in a three-closed-loop control framework of PMSM. Then, the design method of the controller for each loop and the NDOB are presented, the parameter-tuning method based on bandwidth is demonstrated, and the convergence of the NDOB is proved. Furthermore, to improve the searching and tracking efficiency of wide-field survey telescopes, the nonlinear tracking differentiator (NTD) was modified to plan the transition process of the position loop, which only needs to set the maximum speed and acceleration of the telescope. Finally, simulations and experiments were performed on a 2.5-m-wide field survey telescope. The experimental results verify that the proposed NCADS method has a better anti-disturbance performance and higher tracking precision than the conventional method, and the improved NTD method does not need to tune parameters and achieved a fast and smooth transition process of the position loop. [ABSTRACT FROM AUTHOR]

Y-doping can effectively improve the performance of HfO x -based resistive random-access memory (RRAM) devices, but the underlying physical mechanism of Y-doping affecting the performance of HfO x -based memristors is still missing and unclear. Although impedance spectroscopy (IS) has been widely used to investigate impedance characteristics and switching mechanisms of RRAM devices, there is less IS analysis on Y-doped HfO x -based RRAM devices as well as devices at different temperatures. Here, the effect of Y-doping on the switching mechanism of HfO x -based RRAM devices with a Ti/HfO x /Pt structure were reported using current–voltage characteristics and IS. The results indicated that doping Y into HfO x films could decrease the forming/operate voltage and improve the RS uniform. Both doped and undoped HfO x -based RRAM devices obeyed the oxygen vacancies (V O) conductive filament model along the grain boundary (GB). Additionally, the GB resistive activation energy of the Y-doped device was inferior to that of the undoped device. It exhibited a shift of the V O trap level towards the conduction band bottom after Y-doping in the HfO x film, which was the main reason for the improved RS performance. [ABSTRACT FROM AUTHOR]

In the two-step preparation of perovskite solar cells, the ambient temperature is the main factor affecting the performance of the cells and controlling the crystallization of perovskite films. In this paper, we demonstrate the importance of resting temperature in the preparation of perovskite solar cells based on the morphology of PbI2 film and perovskite film. The ambient temperature around the PbI2 film directly influences its morphology after resting, and then affects the morphology of the annealed perovskite film. The experimental results show that the optimum ambient temperature for resting PbI2 is 28 °C at which solar cell conversion efficiency is improved to 22.2%. This study is of great significance to the preparation of high-performance PVSCs. [ABSTRACT FROM AUTHOR]

Objective. From the perspective of metabolomics, this study compares the metabolomics characteristics of feces and urine between children with spleen-deficiency and healthy children to explain the scientific connotation of children with spleen-deficiency susceptibility to digestive system diseases from the metabolic level and provide a scientific basis for further research. Methods. This study included 20 children with spleen-deficiencies and 17 healthy children. Children's symptom scores, height, and weight were recorded in groups, and feces and urine samples were collected. The samples were detected using ultrahigh-performance liquid chromatography-mass spectrometry. The data were analyzed using multivariate statistical analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Related differential metabolites were identified through database comparisons between two groups based on the MS and KEGG. Results. Compared to healthy children, the metabolites glucuronic acid, xanthine, and indole-3-acetaldehyde tend to be reduced in children with spleen-deficiency. Moreover, these children showed an increase in metabolites such as quinic acid, adenine, 4-methyl-5-thiazole-ethanol, 3-formyl indole, and 5-hydroxy indole-3-acetic acid. The condition affected many of the critical metabolic pathways, including the metabolism of tryptophan, cysteine, methionine, and pentose phosphate. Conclusion. The children with spleen-deficiency had disorders at the metabolic level, which might be due to factors such as diet, personal preferences, and genes, leading to various symptoms, making spleen-deficiency children more prone to suffer from digestive diseases than healthy children. The results set a basis for the research on children's TCM constitution, which can be a reference to further studies to deal with the spleen-deficiency. [ABSTRACT FROM AUTHOR]

A sensitive element for realizing the pressure sensing at high temperature is experimentally prepared using the microelectromechanical systems (MEMS) fabrication technology and consists of a 50-μm-thick, 1400-μm-wide square multilayer component membrane (including silicon, silicon dioxide, and silicon nitride) and a monolayer graphene with meander pattern. The prepared sample is characterized and analyzed using various techniques including atomic force microscopy, Raman spectroscopy, and the finite element method. The strain distribution in the pressed membrane is simulated by the finite element method. The pressure sensing based on the monolayer graphene with meander pattern can be realized according to the strain distribution and the high-temperature measurements for the sensitive element. Accordingly, a new pressure sensor based on the sensitive element is proposed for exploring the sensing performance depending on the piezoresistive property of monolayer graphene at high temperature. The sensing performance can be obtained by the theoretical analysis for electromechanical measurements at high temperature for the sensitive element. The results demonstrate that the performances of the sensor are excellent at high temperature. In particular, the sensitivity is much higher than that of previous high-temperature MEMS pressure sensors. Our results can provide insights for realizing the high-temperature applications of graphene in electronic devices. [ABSTRACT FROM AUTHOR]

Near-interface oxide traps severely affect the voltage stability of silicon carbide metal-oxide-semiconductor devices. In this work, electron cyclotron resonance microwave nitrogen plasma and electron cyclotron resonance microwave nitrogen-hydrogen-mixed plasma were used to passivate near-interface oxide traps in silicon carbide metal-oxide-semiconductor capacitors. An improved low-temperature midgap voltage drift method was proposed to evaluate the voltage stability of silicon carbide metal-oxide-semiconductor capacitors. Results showed that the effect of passivating near-interface oxide traps and voltage stability could be improved by increasing the nitrogen passivation time. However, excessive nitrogen passivation created deep-level interface traps that degraded the interface quality, and a small amount of hydrogen could passivate the deep-level traps produced by the excess nitrogen. As a result, the samples subjected to the passivation process with the nitrogen-hydrogen-mixed plasma had a smaller flat-band voltage drift and more stable carbide metal-oxide-semiconductor capacitors than the samples subjected to nitrogen plasma. However, the excessive introduction of hydrogen also produced additional defects, consequently making the stability of the metal-oxide-semiconductor devices sensitive to the time of the passivation process by nitrogen-hydrogen-mixed plasma. Therefore, the suitable time of mixed plasma passivation is crucial to the improvement of the stability of devices. [ABSTRACT FROM AUTHOR]

Photogenerated carrier behavior at a CO2/Cs2AgBiBr6 quantum dot (QD) interface is investigated. In situ photovoltage spectra reveal electron transfer from the Cs2AgBiBr6 QDs to CO2. Moreover, this carrier transfer prefers Bi3+ sites (over Ca+ and Ag+ sites) due to them exhibiting the lowest adsorption energy (Eads = −0.125 eV) and CO2–Bi3+ interactions being more stable. [ABSTRACT FROM AUTHOR]

Interface modification is an important means to enhance the photovoltaic performance of quantum dot sensitized solar cells (QDSCs). The TiO2/CdS/CdSe solar cells are sensitized with CdS QDs and CdSe QDs, which inevitably introduces a new interface to form a recombination center. Therefore, it is necessary to coat a passivation layer in order to effectively inhibit charge recombination at the CdS/CdSe interface. In this work, CuInS2 (CIS) has been introduced into the CdS/CdSe QD system as an inner passivation layer and the CdS/CIS/CdSe photoanode structure has been fabricated in an environmentally friendly manner. The extracted charge amount (Q) is used to express the charge separation efficiency, indicating that we have obtained outstanding charge extraction efficiency in CIS based CdS/CdSe QDSCs. As a result, the photocurrent density of the TiO2/CdS/CIS/CdSe photoanode significantly has increased from 19.01 mA cm−2 to 22.74 mA cm−2 (TiO2/CdS/CdSe photoanode), which demonstrates a higher photoconversion efficiency of 4.52% in comparison with that of TiO2/CdS/CdSe photoanode. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) plays an essential role in the carbon cycle and global warming mitigation, and it varies spatially in relation to other soil and environmental properties. But the national distributions and the impact mechanisms of SOC remain debated in China. Therefore, how soil texture and climate factors affect the SOC content and the regional differences in SOC content were explored by analyzing 7857 surface soil samples with different land-use. The results showed that the SOC content in China, with a mean value of 11.20 g·kg−1, increased gradually from north to south. The SOC content of arable land in each geographical area was lower than in grassland and forest-land. Although temperature also played a specific role in the SOC content, precipitation was the most critical climate factor. The SOC content was positively correlated with the silt and clay content. The lower the temperature, the greater the effect of environmental factors on SOC. In contrast, the higher the temperature, the more significant impact of soil texture on SOC. The regional difference in SOC highlights the importance of soil responses to climate change. Temperature and soil texture should be explicitly considered when predicting potential future carbon cycle and sequestration. [ABSTRACT FROM AUTHOR]

Lithium ion battery is a complex system, and any change in device parameters may significantly affect the overall performance. The prediction of battery behavior based on theoretical simulation is of great significance. In this work, the battery performance with LiNi1/3Co1/3Mn1/3O2 electrodes of different active material loading amounts was theoretically investigated, such as battery rate performance, capacity decay rate, energy and power density, SOC (State of Charge) change, temperature response, and heat source distribution. A 1D electrochemical–3D thermal coupling model was established, and the accuracy and predictability of the model were verified by experiments. An in-depth analysis of batteries under different discharge rates and batteries with different electrode loading amounts is carried out. The results show that the rate performance and capacity change with different electrode loading amounts, which is attributed to the variation in lithium ion diffusion. At the same time, the change in load affects the growth of lithium dendrites and the distribution of SOC, resulting in the thermal runaway of the battery and shortening the battery life. [ABSTRACT FROM AUTHOR]

The high demand for pressure devices with miniaturization and a wide bearing range has encouraged researchers to explore new high-performance sensors from different approaches. In this study, a sensitive element based on graphene in-plane compression properties for realizing pressure sensing is experimentally prepared using microelectromechanical systems (MEMS) fabrication technology; it consists of a 50 µm thick, 1400 µm wide square multilayer component membrane and a graphene monolayer with a meander pattern. The prepared sample is extensively characterized and analyzed by using various techniques, including atomic force microscopy, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, COMSOL finite element method, and density functional theory. The sensing performance of the new pressure sensor based on the sensitive element are obtained by theoretical analysis for electromechanical measurements of the sensitive element before and after low-temperature annealing in atmosphere. Results demonstrate that atmospheric annealing at 300 °C enhances the pressure sensing sensitivity by 4 times compared to pristine graphene without annealing, which benefits from the desorption of hydroxyl groups on the graphene surface during annealing. The sensitivity is comparable and even better than that of previous sensors based on graphene in-plane properties. Our results provide new insights into realizing high-performance MEMS devices based on 2D sensitive materials. [ABSTRACT FROM AUTHOR]

CsPbBr3 perovskite exhibits potential application in photocatalytic CO2 reduction into valuable chemical fuels; however, enhancing carrier separation capability of the CsPbBr3 and fully understanding the CO2 reduction reaction process are still imperative. Herein, a new series of xSnS2/CsPbBr3 nanocrystals (NCs)‐y heterostructures are developed, which exhibit better catalytic activity in comparison with pure CsPbBr3 NCs. Interface and surface carrier dynamic investigation reveals that this heterojunction structure can effectively improve carrier separation efficiency. Based on the interfacial electric field direction of CsPbBr3 to SnS2, it is suggested that SnS2/CsPbBr3 NC heterostructure satisfies Z‐scheme transfer dynamics. Meanwhile, by the aid of in situ surface photovoltage, it is experimentally confirmed there is dynamic carrier interaction between CO2 molecules and the SnS2/CsPbBr3 NCs photocatalyst under irradiation, and a photocatalytic CO2 reduction mechanism is thus proposed. This work expands the awareness of the interaction between CO2 and the photocatalyst, which can be strongly influenced by carrier separation efficiency at the photocatalyst heterojunction. [ABSTRACT FROM AUTHOR]

Self-sovereign identity authentication protocol is an active research topic in the field of identity authentication and management. However, the current SSI authentication protocols pay little attention to privacy protection and the fine-grained access control. Therefore, a secure and decentralized SSI authentication protocol with privacy protection and fine-grained access control is proposed. Firstly, the formal model of SSI including the SDPP-SSI identity model and management model is presented. And then, based on the federated blockchain, the distributed identifier is used as a global identifier for users in the decentralized domain. Finally, the verifiable statement is encapsulated using a policy control signature supporting privacy protection to develop the user's access control for identity registration in the centralized domain. Compared with the related work (Lin 2018, Zhu 2018, Stokkink 2018, Hammudoglu 2017, Othman 2017, Abraham 2018, Guan 2019, Lin 2019) from controllability, security, flexibility, privacy protection, authentication and fine-grained access control, the proposed SSI authentication protocol not only meets controllability, authentication, and flexibility, but also supports privacy protection and fine-grained access control. [ABSTRACT FROM AUTHOR]

Ferroelectric hafnium oxide (HfO2) thin film has been widely studied as a promising material candidate for microelectronic devices. In this paper, HfO2/Hf/HfO2 stacked films were deposited by reactive magnetron sputtering to investigate the effects of metal Hf on the phase transition and electric properties. An interesting phenomenon is that HfO2 film inserted with a thin layer of metal Hf exhibits ferroelectricity after high-field cycling (wake-up). The generation of ferroelectricity is due to a region in HfO2 film with a gradient distribution of oxygen vacancies resulting in the formation of orthorhombic HfO2, which is caused by the oxidation of metal Hf in HfO2 film. Inserted with 0.2-nm-thick metal Hf layer, the stacked film shows the coercive field of 3.4 MV/cm and remanent polarization of 4.2 μC/cm2, respectively. An increase in the Hf layer thickness from 0.2 to 1.5 nm causes the leakage current density of the stacked film increasing from 8.2 × 10–6 to 6.2 × 10–4 A/cm2. The results provide a strong evidence for the important role of inhomogeneous oxygen vacancies played in introduction of the ferroelectricity of HfO2 film. [ABSTRACT FROM AUTHOR]

Infrared small-target detection has widespread influences on anti-missile warning, precise weapon guidance, infrared stealth and anti-stealth, military reconnaissance, and other national defense fields. However, small targets are easily submerged in background clutter noise and have fewer pixels and shape features. Furthermore, random target positions and irregular motion can lead to target detection being carried out in the whole space–time domain. This could result in a large amount of calculation, and the accuracy and real-time performance are difficult to be guaranteed. Therefore, infrared small-target detection is still a challenging and far-reaching research hotspot. To solve the above problem, a novel multimodal feature fusion network (MFFN) is proposed, based on morphological characteristics, infrared radiation, and motion characteristics, which could compensate for the deficiency in the description of single modal characteristics of small targets and improve the recognition precision. Our innovations introduced in the paper are addressed in the following three aspects: Firstly, in the morphological domain, we propose a network with the skip-connected feature pyramid network (SCFPN) and dilated convolutional block attention module integrated with Resblock (DAMR) introduced to the backbone, which is designed to improve the feature extraction ability for infrared small targets. Secondly, in the radiation characteristic domain, we propose a prediction model of atmospheric transmittance based on deep neural networks (DNNs), which predicts the atmospheric transmittance effectively without being limited by the complex environment to improve the measurement accuracy of radiation characteristics. Finally, the dilated convolutional-network-based bidirectional encoder representation from a transformers (DC-BERT) structure combined with an attention mechanism is proposed for the feature extraction of radiation and motion characteristics. Finally, experiments on our self-established optoelectronic equipment detected dataset (OEDD) show that our method is superior to eight state-of-the-art algorithms in terms of the accuracy and robustness of infrared small-target detection. The comparative experimental results of four kinds of target sequences indicate that the average recognition rate Pavg is 92.64%, the mean average precision (mAP) is 92.01%, and the F1 score is 90.52%. [ABSTRACT FROM AUTHOR]

Purpose: As an epigenetic regulation mechanism after transcription, RNA modification is installed by endogenous "writer" enzymes and is widely involved in a variety of physiological processes, including cancer progression. This study explored the RNA modification patterns of cervical cancer to clarify overall effect of RNA modification on tumor microenvironment (TME) characteristics and immune/targeted therapy. Methods: 26 RNA modification "writers" were clustered, and the RNA modification patterns and TME characteristics of cervical cancer patients in TCGA were systematically evaluated. Based on differentially expressed genes (DEGs) between different RNA modification patterns, an RNA modification "writer" score (WM score) system was developed to assess the RNA modification of a single sample. Results: Two different RNA modification patterns of cervical cancer were identified, and these patterns were significantly related to the prognosis and TME infiltration characteristics of patients. WM score was an independent risk factor for the prognosis of cervical cancer. High WM score was characterized by poor prognosis, low immune infiltration and low tumor mutation burden (TMB), while low-WM score was related to relatively long overall survival (OS), more immune components in TME and increased TMB. In addition, the low-WM score group was expected to be more sensitive to programmed cell death protein 1 (PD-1) therapy and showed lower predicted IC50 of chemotherapy drugs paclitaxel and cisplatin treatment. Conclusions: This study identified and characterized RNA modification patterns, and clarified potential relationship between RNA modification patterns and immune infiltration characteristics and immunotherapy of cervical cancer, offering a new evaluation scheme for treatment of cervical cancer patients. [ABSTRACT FROM AUTHOR]

Decorating a high-efficiency oxygen evolution reaction (OER) electrocatalyst as a cocatalyst on an α-Fe2O3 photoanode is known to be one of the most efficient methods to improve the photoelectrochemical (PEC) water oxidation activity. In our work, different from traditional methods of transition metal sulfide cocatalyst synthesis, an NiFeSx–decorated Ti-Fe2O3 photoanode is synthesized through a simple one-step electrodeposition method, which benefits the interface between Ti-Fe2O3 and NiFeSx. With the help of this excellent OER electrocatalyst, the photocurrent density of the NiFeSx–Ti-Fe2O3 photoanode rises to 3 mA cm−2 at 1.23 V vs. RHE, which is 2.5 times greater than the photocurrent of Ti-Fe2O3. Moreover, the onset potential of NiFeSx–Ti-Fe2O3 shifts negatively by 170 mV compared with that of pure Ti-Fe2O3. Furthermore, surface photovoltage spectroscopy (SPV) and transient photovoltage (TPV) techniques and photoelectrochemical impedance spectroscopy (PEIS) were used to analyze the true effects of NiFeSx as an efficient cocatalyst for enhancing the PEC performance of the NiFeSx–Ti-Fe2O3 photoanode. This work provides a simple method for loading a low-cost and efficient cocatalyst to modify a Ti-Fe2O3 photoanode for the PEC water oxidation reaction. [ABSTRACT FROM AUTHOR]

Efficiency and privacy are the key aspects in content extraction signatures. In this study, we proposed a Secure and Efficient and Certificateless Content Extraction Signature with Privacy Protection (SECCESPP) in which scalar multiplication of elliptic curves is used to replace inefficient bilinear pairing of certificateless public key cryptosystem, and the signcryption idea is borrowed to implement privacy protection for signed messages. The correctness of the SECCESPP scheme is demonstrated by the consistency of the message and the accuracy of the equation. The security and privacy of the SECCESPP scheme are demonstrated based on the elliptic curve discrete logarithm problem in the random oracle model and are formally analyzed with the formal analysis tool ProVerif, respectively. Theory and experimental analysis show that the SECCESPP scheme is more efficient than other schemes. [ABSTRACT FROM AUTHOR]

Although silicon carbide (SiC) metal oxide semiconductor field-effect transistors (MOSFETs) are commercially available, bias temperature instability (BTI) defined as shifts in Vth in SiC MOSFET and Vfb in MOS capacitor after the device is operated at a high temperature, seriously affects device reliability and limits further commercial applications. These instabilities are mainly attributed to charge trapping at and near the SiC/SiO2 interface and mobile ions in a gate oxide. The consequences of Vth instability are serious and can worsen the performance and lifetime of SiC MOS devices. In this review, the SiC/SiO2 interface issue is introduced, and BTI occurring in current SiC MOS devices is described in detail. Vth/Vfb instability behavior induced by measurement and stress conditions, microscopic defects and instability mechanisms, recent measurement techniques of near-interfacial oxide traps, and BTI improvement resulting from the fabrication processes are described. BTI improvement mainly involves the control of charge trapping and movements of ions. The fabrication processes are related to oxidation and pre- and post-oxidation treatments. This review can help deepen our understanding of BTI and reduce its influence on SiC MOS devices performance. [ABSTRACT FROM AUTHOR]

Security protocols are integral to the protection of cyberspace against malicious attacks. Therefore, it is important to be confident in the security of a security protocol. In previous years, people have worked on security of security protocol abstract specification. However, in recent years, people have found that this is not enough and have begun focusing on security protocol implementation. In order to evaluate the security of security protocol implementations, in this paper, firstly, we proposed the Message Construction to Security Protocol Implementation (MCSPI), a message construction method based on application programming interface (API) traces, which automatically generates the constructed client valid request messages. Then, we presented the Security Analysis Scheme (SAS), a security analysis scheme that generates an abstract model of a security protocol server. Next, we proposed a security analysis method to evaluate the security of security protocol implementations on the basis of constructed client request messages generated with MCSPI, corresponding to the server-side response message and server-side abstract model produced by SAS. Finally, we implemented the Security Protocol Implementation Analysis (SPIA) tool to generate client valid request messages and a server-side abstract model to assist in evaluating security protocol implementations. In our experiments, we tested Tencent QQ mail system version 2017 and RSAAuth system and found that RSAAuth is vulnerable and its server has only security checks for user password, while Tencent QQ mail system version 2017 is more secure and has strong security restrictions at server-side besides security checks for user password. [ABSTRACT FROM AUTHOR]

Tire force distribution with the consideration of practical constraints is a key part of automatic driving. This paper is intended to improve the operational capability of the vehicle under low friction coefficient. The speed and front wheel angle are restricted within a specific range caused by the limitation of executable drive space, which is defined as an input constrained problem of the nonlinear system. The hierarchical design concept is adopted in this paper, including algorithms of both control and allocation to determine the driving performance cooperatively. The methodology of multi-input and multi-output sliding mode control (MIMO SMC) is applied in the high-level controller to guarantee the vehicle system stable. Confronted with circumstances that the vehicle may be seriously unstable due to longitudinal forces and lateral forces beyond the feasible region in the friction circle, the scheme of dynamic adjustment of control target is provided owing to there is no reasonable solution for tire force distribution in the low-level controller. The coefficients of reconstruction and attenuation are introduced to reconstruct the optimized controller and weaken inputs of the closed loop system, respectively. The simulation results verify that the proposed design can redistribute generalized forces and moments between the wheels especially for the poor road condition. [ABSTRACT FROM AUTHOR]

Semiconductor electrodes integrated with cocatalysts are key components of photoelectrochemistry (PEC)‐based solar‐energy conversion. However, efforts to optimize the PEC device have been limited by an inadequate understanding of the interface interactions between the semiconductor–cocatalyst (sem|cat) and cocatalyst–electrolyte (cat|ele) interface. In our work, we used ferrihydrite (Fh)‐modified Ti–Fe2O3 as a model to explore the transfer process of photogenerated charge carriers between the Ti–Fe2O3–Fh (Ti–Fe2O3|Fh) interface and Fh‐electrolyte (Fh|ele) interface. The results demonstrate that the biphasic structure (Fh/Ti–Fe2O3) possesses the advantage that the minority hole transfer from Ti–Fe2O3 to Fh is driven by the interfacial electric field at the Ti–Fe2O3|Fh interface; meanwhile, the holes reached at the surface of Fh can rapidly inject into the electrolyte across the Fh|ele interface. As a benefit from the improved charge transfer at the Ti–Fe2O3|Fh and Fh|ele interface, the photocurrent density obtained by Fh/Ti–Fe2O3 can reach 2.32 mA cm−2 at 1.23 V versus RHE, which is three times higher than that of Ti–Fe2O3. Water splitting: The excellent performance of ferrihydrite (Fh)/Ti–Fe2O3 is attributed to the unhindered charge transfer at the Ti–Fe2O3|Fh and Fh|electrolyte interfaces. As a benefit from this improved charge transfer, the photocurrent density obtained by Fh/Ti–Fe2O3 can reach 2.32 mA cm−2 at 1.23 V versus the reversible hydrogen electrode, which is three times higher than that of Ti–Fe2O3. [ABSTRACT FROM AUTHOR]

Background. Immunotherapy for cervical cancer with type I interferon (IFN) is limited because of the cytotoxicity that accompanies the high doses that are administered. In this study, we investigated the utilization of amniotic fluid-derived mesenchymal stem cells (AF-MSCs) as a means for delivering IFNα to local tumor sites for the suppression of cervical cancer in a mouse model using HeLa cell xenografts. Methods. The tumor tropism ability of AF-MSCs and AF-MSCs genetically modified to overexpress IFNα (IFNα-AF-MSCs) was examined through Transwell in vitro and through fluorescent images and immunohistochemistry in a mouse model. Tumor size and tumor apoptosis were observed to evaluate the efficacy of the targeting therapy. Mechanistically, tumor cell apoptosis was detected by cytometry and TUNEL, and oncogenic proteins c-Myc, p53, and Bcl-2 as well as microvessel density were detected by immunohistochemistry. Results. In this model, intravenously injected AF-MSCs selectively migrated to the tumor sites, participated in tumor construction, and promoted tumor growth. After being genetically modified to overexpress IFNα, the IFNα-AF-MSCs maintained their tumor tropism but could significantly suppress tumor growth. The restrictive efficacy of IFNα-AF-MSCs was associated with the suppression of angiogenesis, inhibition of tumor cell proliferation, and induction of apoptosis in tumor cells. Neither AF-MSCs nor IFNα-AF-MSCs trigger tumor formation. Conclusions. IFNα-AF-MSC-based therapy is feasible and shows potential for treating cervical cancer, suggesting that AF-MSCs may be promising vehicles for delivering targeted anticancer therapy. [ABSTRACT FROM AUTHOR]

Summary: The clustered regularly interspaced short palindromic repeats‐associated protein 9 (CRISPR/Cas9) system is a powerful tool for editing plant genomes. Efficient genome editing of grape (Vitis vinifera) suspension cells using the type II CRISPR/Cas9 system has been demonstrated; however, it has not been established whether this system can be applied to get biallelic mutations in the first generation of grape. In this current study, we designed four guide RNAs for the VvWRKY52 transcription factor gene for using with the CRISPR/Cas9 system, and obtained transgenic plants via Agrobacterium‐mediated transformation, using somatic embryos of the Thompson Seedless cultivar. Analysis of the first‐generation transgenic plants verified 22 mutant plants of the 72 T‐DNA‐inserted plants. Of these, 15 lines carried biallelic mutations and seven were heterozygous. A range of RNA‐guided editing events, including large deletions, were found in the mutant plants, while smaller deletions comprised the majority of the detected mutations. Sequencing of potential off‐target sites for all four targets revealed no off‐target events. In addition, knockout of VvWRKY52 in grape increased the resistance to Botrytis cinerea. We conclude that the CRISPR/Cas9 system allows precise genome editing in the first generation of grape and represents a useful tool for gene functional analysis and grape molecular breeding. [ABSTRACT FROM AUTHOR]

Abstract: Although NiCoP has attracted much attention in the field of electrocatalysis, the study of its photocatalytic activity and mechanism have been somewhat limited. NiCoP/g‐C3N4, synthesized by simple one‐pot method, is a highly efficient photocatalyst for hydrogen production from water. NiCoP/g‐C3N4 exhibits a hydrogen evolution rate of 1643 μmol h−1 g−1, which is 21 times higher than that of bare g‐C3N4. The excellent performance is due to a combination of improved separation efficiency and effective charge transfer efficiency. The photogenerated charge behavior is characterized by the surface photovoltage (SPV), transient photovoltage (TPV), and photoluminescence spectroscopy. The photogenerated charge transport is investigated by electrochemical impedance spectroscopy and polarization curve. Moreover, the effective charge transfer efficiency was measured according to the mimetic apparent quantum yield. SPV and TPV measurements, whereby 10 vol % of a triethanolamine–water mixture was added into the testing system, were taken to simulate the real atmosphere for photocatalytic reaction, which can give rise to the photogenerated charge transfer process. A possible photocatalytic mechanism was also proposed. This study may provide an efficient theoretical basis to design transition metal phosphide cocatalyst‐modified photocatalysts. [ABSTRACT FROM AUTHOR]

Bimetallic materials hold promise for improving catalyst activity, yet little is known about the photocatalytic mechanism that these systems undergo during photocatalytic reaction that lead to efficient catalyst. Herein, we synthesized g-C3N4 combined with PtNi x, which shows much higher photocatalytic activity than that of pure g-C3N4 and achieves the highest H2 evolution rate of 8456 μmol h−1 g−1 for 2.5 % PtNi x/g-C3N4. The excellent photocatalytic activity resulted from the enhanced charge-separation efficiency compared to the pristine g-C3N4, which was proved by surface photovoltage, photoluminescence, and transient photovoltage spectra. Electrochemical impedance spectroscopy in the dark further confirms the ability of charge transfer of 2.5 % PtNi x/g-C3N4 is superior to that of pure g-C3N4. This effective separation efficiency gives rise to the observed excellent photocatalytic activity. This study not only provides us with an efficient catalyst for water splitting, but opens new avenues for designing and developing platinum-based photocatalysts. [ABSTRACT FROM AUTHOR]

In this paper, a wafer-level package with hermetic sealing by low-temperature Cu/Sn transient liquid phase (TLP) bonding for a micro-electromechanical system was introduced. A Cu bump with a Sn cap and sealing ring were fabricated simultaneously by electroplating. The model of Cu/Sn TLP bonding was established and the thicknesses of Cu and Sn were optimized after a series of bonding experiments. Cu/Sn wafer-level bonding was undertaken at 260°C for 30 min under a vacuum condition. An average shear strength of 50.36 MPa and a fine leak rate of 1.9 × 10 atm cc/s were achieved. Scanning electron microscope photos of the Cu/Sn/Cu interlayers were presented, and energy dispersive x-ray analysis was conducted simultaneously. The results showed that the Sn was completely consumed to form the stable intermetallic compound CuSn. An aging test of 200 h at 200°C was conducted to test the performance of the hermetic sealing, while the results of shear strength, fine leak rate and bonding interface were also set out. [ABSTRACT FROM AUTHOR]

Nickel phosphide (Ni2P) was used as an excellent water oxidation cocatalyst for photoelectrochemical (PEC) water splitting, which could significantly promote the hole injection efficiency and suppress the back reaction of water oxidation over a Ti4+ doped Fe2O3 photoanode. [ABSTRACT FROM AUTHOR]

Human endometrial tissue has become an attractive source of mesenchymal stem cells (MSCs) for cell-based therapies because these MSCs can be easily harvested and have tumour tropism as well as reduced immunogenic and inflammatory properties. Our study aimed to obtain and characterise human endometrial mesenchymal stem cells (EMSCs) and assess their endometriosis tropism. EMSCs were successfully isolated from the endometrium of women undergoing laparoscopy for idiopathic infertility. The EMSCs presented a fibroblast-like morphology during culture. Flow cytometry analyses showed that the cells were positive for the specific stem cell markers CD73, CD90, CD105, CD166, and HLA-ABC (major histocompatibility complex class I (MHC I)) but negative for CD14, CD34, CD45, and HLA-DR (MHC II). Reverse transcription polymerase chain reaction results showed that the EMSCs expressed the stem cell marker OCT4. The EMSCs could differentiate into osteocytes, adipocytes, and chondrocytes under certain conditions. The EMSCs had a high tropism to endometriosis without tumourigenicity. This study enhances the possibility of using EMSCs as drug carriers in human cell-based therapies. Meanwhile, future research could also focus on developing targeted therapies for endometriosis. [ABSTRACT FROM AUTHOR]

Anatase TiO2 nanowire (NW) films modified with inverted type-I CdS/CdSe core/shell structure QDs have been successfully prepared by the post synthesis ligand-assisted technique. Surface photovoltage (SPV), transient photovoltage (TPV) and transient photocurrent (TPC) measurements demonstrate that CdS/CdSe core/shell structure QD-sensitized TiO2 NWs electrodes favor photoexicited electron injection and charge transfer due to the special photo-electronic features of CdS/CdSe core/shell structure QDs. With a polysulfide electrolyte, the maximum conversion efficiency was 2.18% for CdS/CdSe QDs with the CdSe shell being 4.4 nanometers thick; a PCE of 0.07% for CdS QDs and a PCE of 0.63% for CdSe QDs were obtained under illumination at 100 mW cm−2. The results reveal that the CdS/CdSe core/shell structure QDs sensitized TiO2 NW electrodes have promising applications in solar cells. [ABSTRACT FROM AUTHOR]